L-23 Super Blanik Rigging (assembly/disassembly) Guide Maj Carl Kerns <gliderpilot2@cox.net> The L-23 Blanik is a difficult Sailplane to rig (assemble). The wings are heavy and are secured via a single main spar pin and a drag pin on each side. When reading the extremely vague aircraft manual, it would appear that three persons are required. We have proven this to work IF all participants are strong, healthy, experienced, there is NO wind, and have a wing stand in their possession! However, normally it will take at least five, reasonably strong individuals to safely assemble the sailplane. The following step by step instructions are provided by the Las Vegas area Civil Air Patrol glider program. This unit trailers their L-23 Super Blanik two to three times a year to different functions and for annual maintenance. The instructions are being offered to help those rigging a L-23 Super Blanik and are provided in an effort to fill this gap in information for all L-23 glider operations. On the legal side, we accept no responsibility associated with the use of these instructions and the user accepts all responsibility for suitability and accuracy. Tools: Assembling the tools needed is the first step. The following tools are recommended. Page 1 of 12
Brass, Lead, or hard & heavy plastic hammer for installing wing pins. Being thin enough to fit in the wing/fuselage gap is a plus when installing the drag pin but not necessary. CAUTION: NEVER use a standard hammer for the wing pins, as damage to the hardened pins and or the aircraft will likely occur and will increase the potential for sharp metal fragments to be ejected with potentially serious injury to eyes and body. Medium sized punch (6-8 ). This will be used to knock pins out during disassembly. Needle nose pliers with long tips. These are used for the safety (clips) and aileron linkage pins as well as safety wire installation. Common (flat) screwdriver, medium sized. This is used for attaching the ground straps at the aileron linkage pins. Wing stand (three to five foot tall). The wing stand needs to be able to support 300-400 Lbs without damaging the wing. The device will need to be able to support 70-80% of the wing total weight without easily tipping or leaning! Telescopic magnet (optional). This will be handy if someone drops a clip inside the aircraft or wing during assembly. Two old vehicle tires (optional). These can be used to set the wing down onto if that becomes necessary and makes a great tail stand afterward. Materials: The following material will also be needed. Suitable grease (must be waterproof) Aviation safety wire (six inches) Preparation: Preparation is critical. Find a suitable area to do this. A suitable area will be flat and smooth (pavement is preferred), will be sheltered from the wind as much as possible and have 50-60 feet of clear, unobstructed space behind the trailer. CAUTION: Do not try to assemble/disassemble this aircraft in winds above 10 mph without substantially more help and never above 15 mph. An additional adjacent space able to accommodate the assembled glider will also be required. Assemble your team, tools and materials, and position and secure your trailer as required. Team Briefing: Give a safety briefing to your team that includes an overview of the sequence of events. Walking them through each step before that step is started would also be a tremendous help. Having them read these instructions would also be a great start. Assembly: Open the trailer and secure any doors that may swing shut on the glider or team members as the glider is removed. Ensure both ends of the trailer are supported so it doesn t tip as the glider components are removed. Secure any ramps provided and remove any attachments securing the glider to the trailer. With one person on the tail for steering and vertical stability, slide the fuselage out of the trailer and position it where you are going to assemble the glider. Be sure there is ample room for the fully assembled glider. Depending on the stability of the fuselage cradle supplied, or if it is windy, leave this person on the tail for fuselage stability. Remove any lock pins for the fuselage Page 2 of 12
cradle (if any) utilizing the wing attachment points so it will not interfere with the wing installation, but do NOT remove the cradle or device stabilizing the fuselage at this time. Open the canopy and ensure the air brake lever is in the closed and locked position, lube the fuselage attachment points and close the canopy. Set up the wing stand and place the tools and attachment parts close to the fuselage where they can be easily reached but not kicked! Install the trailing edge protector on the first wing (if available) on the wing where the trailing edge meets the fuselage. Page 3 of 12
STOP HERE and brief your team. Attaching the wings are the most strenuous and difficult part of the assembly process. EXTREME care is needed so no one gets injured and the glider is not damaged. The pin installer and wingtip handler will be the team s most experienced people. WALK YOUR TEAM TROUGH THE PROCESS (see wing installation below), and be ready with the pin handle in case the wing must be pinned temporarily to allow the team to rest. NOTE: The main spar pin must be completely installed OR the pin handle inserted before allowing the wing to come to rest when mated to the fuselage to prevent damage. Team member assignments: The three strongest team members should take the leading and trailing edges of the wing root (the heaviest point) and the third, the wing tip (this should be someone experienced if possible). The person on the trailing edge should be instructed to handle the wing at the rivet lines only. The last person (team leader) will disconnect the wing from the trailer dolly and (soon after) install the pins attaching the wing and should have the wing pin handle and all other tools and parts readily available. Page 4 of 12
Installing the wing(s): Lube the wing attachment point prior to starting. Remove the wing from the trailer and once it is clear of the trailer roll it flat (top side up) to reduce wind interference and team member strain. The persons on the wing root end should move two feet from the end so the pin installer has room to work. With the person on the tail stabilizing the fuselage, gently and slowly slip the wing into position. The main spar pin holes (both upper AND lower) must be in near perfect alignment before attempting to insert the alignment pin (the long gold colored one pictured above). Fully insert the pin from the top down. Tip: If lining up the pin proves too difficult, tilting the fuselage in the cradle toward the wing may help with the alignment. However, be VERY careful the wing weight is fully supported and does not unexpectedly slip out of the pin brackets! DO NOT ALLOW THE WING TO COME TO REST WITH ANY PINS PARTIALLY INSTALLED, IT CAN POTENTIALLY CAUSE SERIOUS DAMAGE TO THE GLIDER! Once the alignment pin is in, insert the drag pin. Install the drag pin from the front (Note: the bent washer is not defective, it s matched to the shape of the bracket!). Having the drag pin in will help keep the wing aligned while installing the main spar pin. This is a good point to take a break and let your team rest. The next step is the most difficult. Have your team move the wing around slightly until you can easily and freely twist the alignment pin. Have everyone freeze and after one last check for free movement, quickly remove the alignment pin and replace it with the main spar pin and Page 5 of 12
carefully hammer it down with one of the safety pin holes (there are two) facing forward/backward so the safety pin can be covered later by the fairing with the clip installed. Once the main spar pin has been installed (verify the bottom washer flat side is in the right place and the washer is flush and pin installed). Allow the wing to rest on the wing stand. Before the drag pin is installed, the wing tip can be moved forward and backward creating a pinch point at the trailing edge at the fuselage. If a trailing edge protector is not available (see below), EXTREME CAUTION is to be used at this pinch point as getting caught in the pinch will cause SERIOUS injury. This applies to the second wing installation as well. Once the first wing has been installed (main spar pin and drag pin fully installed), make sure the landing gear is in the down and locked position and remove the fuselage cradle. This is also a great time to check the tire pressure for 37 psi. Page 6 of 12
Leave the first wing on the stand and prepare to install the second wing as instructed above. Ensure the first wing is secure and the person formerly on the tail is holding the wingtip as wiggling the second wing back & forth during assembly could knock it off the stand and severely damage the glider and/or injure crew members. Install the second wing. Page 7 of 12
After both wings have been installed, return to the gaps between the wings and fuselage and install the aileron control linkage pins and ground straps. Someone will need to hold the aileron and flight control stick in the right place so the linkage is exposed in the gap. The T shaped pins go in from the top and are secured by a diaper type pin in the hole provided. This can be difficult as the ball part of the connector tends to rotate, preventing a smooth installation, just keep tying and be ready to install the pin with pliers when it lines up! After the aileron connections are made, install the ground strap at both connections. Once this is done, install the gap (fairing) covers being careful not to pull the spring loaded strap toward your face using a screwdriver in the hole. If the screw driver slips, it could stab the team member in the face, or worse, the eye! We use a modified paint can opener (see previous alignment pin photo), which eliminates this risk. Once hooked, return to the leading edge and ensure the centering tab inside the front of the fairing is in the gap and not holding the fairing off the wing. Page 8 of 12
Installing the horizontal stabilizer: Before installing the stabilizer, be sure the locking pin and the twin pins at the rear of the tail above the rudder (see below) are well lubricated. Have the red locking pin readily available. Never use a hammer or similar object during the stabilizer installation. If smacking it with the palm of your hand is not enough, something is not right. DON'T FORCE IT! Remove it and start again and/or check the alignment. As you start, have one person on each end of the stabilizer, one on the control stick in the cockpit, and one (the most experienced) with the pin and directing the installation. The stabilizer is installed by inserting the elevator bar holes (exposed between the elevator control surfaces) onto the pins at the top of the rudder. The person on the control stick will need to be told where to hold the stick so the pins are angled correctly for the installation (roughly 30 degrees up). The pin holder must CAREFULLY guide the stabilizer back onto the pins without damaging the elevator control surfaces against the surrounding panels. Page 9 of 12
After the elevator has been fully installed on the pins, lower the leading edge of the horizontal stabilizer down onto the vertical stabilizer engaging the forward attachment bracket (viewable through the small viewing window at the top of both sides of the vertical stabilizer). If it doesn t line up, the elevator is not all the way on the pins. With the brackets aligned, insert the red pin in the hole at the front of the vertical stabilizer with the hooked end facing up. After being sure the pin is fully installed, rotate the pin 180 degrees (hook facing down) to engage the tab on the bracket that prevents it from coming out when pulled on. Pull vigorously on the pin. Page 10 of 12
If it doesn t come out, safety wire the hooked end of the pin to the loop/tab below it on the vertical stabilizer to prevent its rotation/removal. Once all this is done and the glider is assembled, do not forget to perform a positive control check!!! Page 11 of 12
DE-RIGGING DE-RIG (disassemble) the sailplane by reversing the above process with the following warnings: Before starting to remove the first wing, remember to disconnect the ailerons first, install the trailing edge protector (if available) and remove the drag pin BEFORE attempting to remove the main pin and the wing. Should a trailing edge protector not be available, the person on the wing tip will need to keep the wing far enough forward after the drag pin is removed to keep the trailing edge and the fuselage from damaging each other in a pinching action. EXTREME CAUTION is to be used at this pinch point as getting caught in the pinch will cause SERIOUS injury. When removing the first wing, remember to support the opposite wing using a wing stand and a strong individual on the wing tip. Both wings will need to be lifted some to relieve the weight on the wing pin so the pin will come out without excessive force being used. Before removing the second wing, install the fuselage cradle and have at least one person stabilizing the fuselage. Retract the landing gear. When the wing is pulled free, it is common for the tight fitting main pin bracket to try and pull the fuselage over as it pulls free. Hope this helps! L-23 Rigging Guide (2) Page 12 of 12